package com.wc.alorithm_blue_bridge_history.simulation_match3.G;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2024/3/8 15:28
 * @description
 * 给定一个仅包含数字字符的字符串，请统计一下这个字符串中出现了多少个值为奇数的数位。
 * https://www.lanqiao.cn/problems/16565/learning/?problem_list_id=29&page=1
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        char[] cs = s.toCharArray();
        int res = 0;
        for (char c : cs) {
            if (((c - '0') & 1) == 1) {
                res++;
            }
        }
        System.out.println(res);
    }
}
